Senior Fullstack Software Engineer (Frontend-focused)

Über eco.mio

At eco.mio, we're an ambitious team of 7, spanning 4 nationalities.
Diversity and Work-Life-Balance are important to us. We are a dynamic team with two female co-founders, queer individuals and parents in the team. With our climate tech software plug-in, we're empowering enterprises to achieve their climate goals in business travel by significantly reducing carbon emissions through behavioral change. Together, we're not just building software – we're actively contributing to a more sustainable world.

Your tasks

You will:

Build ad scale features across two products.
Collaborate closely with the CTO on architecture, development practices, and product evolution.
Mentor developers (currently two), champion best practices, and foster a collaborative, high-quality engineering culture.
Serve as a key technical contributor in a fast-paced, mission-driven environment.

Part 1: Impact Suite - Our Established Browser Extension

Ensure reliability and continuous improvement of the extension.
Lead two in-house developers and guide their technical growth.
Solve customer-facing challenges with a pragmatic, solutions-oriented mindset.
Optimize in-house automation and DevOps

Part 2: Recommendation Engine - Our Upcoming Product

Co-architect and build the early-stage platform with the CTO.
Rapidly iterate with early adopters and translate feedback into product decisions.
Own engineering and design choices from day one, shaping the foundation of the new product.

Your skills

Core Skills

Strong JavaScript/TypeScript and React skills; browser extension experience is a plus.
Solid backend experience with any modern framework; Python/Django preferred.
At least 7 years as a fullstack engineer, ideally in a fast-moving startup environment.
Strong frontend expertise, with several years of hands-on experience building modern web applications
Ability to clearly discuss trade-offs and implementation choices with both technical and business stakeholders.
Interest in mentoring and growing more junior team members—this is our first senior engineering hire.

Bonus Points

Experience with cloud infrastructure (AWS preferred).
Experience building recommendation systems or using LLMs.
A hands-on, proactive attitude and passion for sustainability.

What we offer

Ownership to improve scalability, performance, security, and reliability across products.
Close collaboration with our CTO and founders.
80–100% contract, flexible hours, hybrid work (up to 70% remote), Berlin-Neukölln office.
Competitive salary, VSOP participation and vacation policy; plus great perks like Urban Sports, DB travel card and a barista service in the office.
A supportive team culture - fun included (Though, you know, it’s software, so there will be times it will definitely not be fun…

To the Application:

Our job offer Senior Fullstack Software Engineer (Frontend-focused) sounds interesting? Then we are looking forward to receiving your application via: https://ecomio.workwise.io/s/Y9zyOVd-senior-fullstack-software-engineer-frontendfocused